document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=360220>Question 360220</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi, I need some help. I am required to show my work, and I have NO idea how to obtain an answer for this kind of problem. If someone could help me, I would be most appreciative. ;o) \r<BR>\n" );
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document.write( "Directions: Solve\r<BR>\n" );
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document.write( "If a $2000 investment compounded to $2289.80 after 2 yrs, determine the annual interest rate of the investment. Use the compound interent formula  A=P(1+r)^t<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #257024 by </B><A HREF=/tutors/aboutme.mpl?userid=unlockmath><B>unlockmath(1688)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=unlockmath><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=unlockmath><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=257024\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hello, <BR>\n" );
document.write( "First, understand what the letters stand for and then we can plug in the numbers.<BR>\n" );
document.write( " A=P(1+r)^t<BR>\n" );
document.write( "2289.80=2000(1+r)^2<BR>\n" );
document.write( "Expand this out to:<BR>\n" );
document.write( "2289.80=2000(1+2r+r^2)<BR>\n" );
document.write( "rewritten as:<BR>\n" );
document.write( "2289.80=2000r^2+4000r+2000<BR>\n" );
document.write( "Subtract 2289.8 from both sides:<BR>\n" );
document.write( "0=2000r^2+4000r-289.80<BR>\n" );
document.write( "Factor this or could use the quadratic formula to get:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Plug in the values to get:<BR>\n" );
document.write( "7% interest.<BR>\n" );
document.write( "Make sense?<BR>\n" );
document.write( "RJ<BR>\n" );
document.write( "www.math-unlock.com </SPAN>\n" );
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